OK, let's work through this together. We're starting with 390 and we're going to multiply it by 205, which means we add 390 to itself 205 times.
Step 1: 0 + 390 = 390
Step 2: 390 + 390 = 780
Step 3: 780 + 390 = 1170
Step 4: 1170 + 390 = 1560
Step 5: 1560 + 390 = 1950
Step 6: 1950 + 390 = 2340
Step 7: 2340 + 390 = 2730
Step 8: 2730 + 390 = 3120
Step 9: 3120 + 390 = 3510
Step 10: 3510 + 390 = 3900
Step 11: 3900 + 390 = 4290
Step 12: 4290 + 390 = 4680
Step 13: 4680 + 390 = 5070
Step 14: 5070 + 390 = 5460
Step 15: 5460 + 390 = 5850
Step 16: 5850 + 390 = 6240
Step 17: 6240 + 390 = 6630
Step 18: 6630 + 390 = 7020
Step 19: 7020 + 390 = 7410
Step 20: 7410 + 390 = 7800
Step 21: 7800 + 390 = 8190
Step 22: 8190 + 390 = 8580
Step 23: 8580 + 390 = 8970
Step 24: 8970 + 390 = 9360
Step 25: 9360 + 390 = 9750
Step 26: 9750 + 390 = 10140
Step 27: 10140 + 390 = 10530
Step 28: 10530 + 390 = 10920
Step 29: 10920 + 390 = 11310
Step 30: 11310 + 390 = 11700
Step 31: 11700 + 390 = 12090
Step 32: 12090 + 390 = 12480
Step 33: 12480 + 390 = 12870
Step 34: 12870 + 390 = 13260
Step 35: 13260 + 390 = 13650
Step 36: 13650 + 390 = 14040
Step 37: 14040 + 390 = 14430
Step 38: 14430 + 390 = 14820
Step 39: 14820 + 390 = 15210
Step 40: 15210 + 390 = 15600
Step 41: 15600 + 390 = 15990
Step 42: 15990 + 390 = 16380
Step 43: 16380 + 390 = 16770
Step 44: 16770 + 390 = 17160
Step 45: 17160 + 390 = 17550
Step 46: 17550 + 390 = 17940
Step 47: 17940 + 390 = 18330
Step 48: 18330 + 390 = 18720
Step 49: 18720 + 390 = 19110
Step 50: 19110 + 390 = 19500
Step 51: 19500 + 390 = 19890
Step 52: 19890 + 390 = 20280
Step 53: 20280 + 390 = 20670
Step 54: 20670 + 390 = 21060
Step 55: 21060 + 390 = 21450
Step 56: 21450 + 390 = 21840
Step 57: 21840 + 390 = 22230
Step 58: 22230 + 390 = 22620
Step 59: 22620 + 390 = 23010
Step 60: 23010 + 390 = 23400
Step 61: 23400 + 390 = 23790
Step 62: 23790 + 390 = 24180
Step 63: 24180 + 390 = 24570
Step 64: 24570 + 390 = 24960
Step 65: 24960 + 390 = 25350
Step 66: 25350 + 390 = 25740
Step 67: 25740 + 390 = 26130
Step 68: 26130 + 390 = 26520
Step 69: 26520 + 390 = 26910
Step 70: 26910 + 390 = 27300
Step 71: 27300 + 390 = 27690
Step 72: 27690 + 390 = 28080
Step 73: 28080 + 390 = 28470
Step 74: 28470 + 390 = 28860
Step 75: 28860 + 390 = 29250
Step 76: 29250 + 390 = 29640
Step 77: 29640 + 390 = 30030
Step 78: 30030 + 390 = 30420
Step 79: 30420 + 390 = 30810
Step 80: 30810 + 390 = 31200
Step 81: 31200 + 390 = 31590
Step 82: 31590 + 390 = 31980
Step 83: 31980 + 390 = 32370
Step 84: 32370 + 390 = 32760
Step 85: 32760 + 390 = 33150
Step 86: 33150 + 390 = 33540
Step 87: 33540 + 390 = 33930
Step 88: 33930 + 390 = 34320
Step 89: 34320 + 390 = 34710
Step 90: 34710 + 390 = 35100
Step 91: 35100 + 390 = 35490
Step 92: 35490 + 390 = 35880
Step 93: 35880 + 390 = 36270
Step 94: 36270 + 390 = 36660
Step 95: 36660 + 390 = 37050
Step 96: 37050 + 390 = 37440
Step 97: 37440 + 390 = 37830
Step 98: 37830 + 390 = 38220
Step 99: 38220 + 390 = 38610
Step 100: 38610 + 390 = 39000
Step 101: 39000 + 390 = 39390
Step 102: 39390 + 390 = 39780
Step 103: 39780 + 390 = 40170
Step 104: 40170 + 390 = 40560
Step 105: 40560 + 390 = 40950
Step 106: 40950 + 390 = 41340
Step 107: 41340 + 390 = 41730
Step 108: 41730 + 390 = 42120
Step 109: 42120 + 390 = 42510
Step 110: 42510 + 390 = 42900
Step 111: 42900 + 390 = 43290
Step 112: 43290 + 390 = 43680
Step 113: 43680 + 390 = 44070
Step 114: 44070 + 390 = 44460
Step 115: 44460 + 390 = 44850
Step 116: 44850 + 390 = 45240
Step 117: 45240 + 390 = 45630
Step 118: 45630 + 390 = 46020
Step 119: 46020 + 390 = 46410
Step 120: 46410 + 390 = 46800
Step 121: 46800 + 390 = 47190
Step 122: 47190 + 390 = 47580
Step 123: 47580 + 390 = 47970
Step 124: 47970 + 390 = 48360
Step 125: 48360 + 390 = 48750
Step 126: 48750 + 390 = 49140
Step 127: 49140 + 390 = 49530
Step 128: 49530 + 390 = 49920
Step 129: 49920 + 390 = 50310
Step 130: 50310 + 390 = 50700
Step 131: 50700 + 390 = 51090
Step 132: 51090 + 390 = 51480
Step 133: 51480 + 390 = 51870
Step 134: 51870 + 390 = 52260
Step 135: 52260 + 390 = 52650
Step 136: 52650 + 390 = 53040
Step 137: 53040 + 390 = 53430
Step 138: 53430 + 390 = 53820
Step 139: 53820 + 390 = 54210
Step 140: 54210 + 390 = 54600
Step 141: 54600 + 390 = 54990
Step 142: 54990 + 390 = 55380
Step 143: 55380 + 390 = 55770
Step 144: 55770 + 390 = 56160
Step 145: 56160 + 390 = 56550
Step 146: 56550 + 390 = 56940
Step 147: 56940 + 390 = 57330
Step 148: 57330 + 390 = 57720
Step 149: 57720 + 390 = 58110
Step 150: 58110 + 390 = 58500
Step 151: 58500 + 390 = 58890
Step 152: 58890 + 390 = 59280
Step 153: 59280 + 390 = 59670
Step 154: 59670 + 390 = 60060
Step 155: 60060 + 390 = 60450
Step 156: 60450 + 390 = 60840
Step 157: 60840 + 390 = 61230
Step 158: 61230 + 390 = 61620
Step 159: 61620 + 390 = 62010
Step 160: 62010 + 390 = 62400
Step 161: 62400 + 390 = 62790
Step 162: 62790 + 390 = 63180
Step 163: 63180 + 390 = 63570
Step 164: 63570 + 390 = 63960
Step 165: 63960 + 390 = 64350
Step 166: 64350 + 390 = 64740
Step 167: 64740 + 390 = 65130
Step 168: 65130 + 390 = 65520
Step 169: 65520 + 390 = 65910
Step 170: 65910 + 390 = 66300
Step 171: 66300 + 390 = 66690
Step 172: 66690 + 390 = 67080
Step 173: 67080 + 390 = 67470
Step 174: 67470 + 390 = 67860
Step 175: 67860 + 390 = 68250
Step 176: 68250 + 390 = 68640
Step 177: 68640 + 390 = 69030
Step 178: 69030 + 390 = 69420
Step 179: 69420 + 390 = 69810
Step 180: 69810 + 390 = 70200
Step 181: 70200 + 390 = 70590
Step 182: 70590 + 390 = 70980
Step 183: 70980 + 390 = 71370
Step 184: 71370 + 390 = 71760
Step 185: 71760 + 390 = 72150
Step 186: 72150 + 390 = 72540
Step 187: 72540 + 390 = 72930
Step 188: 72930 + 390 = 73320
Step 189: 73320 + 390 = 73710
Step 190: 73710 + 390 = 74100
Step 191: 74100 + 390 = 74490
Step 192: 74490 + 390 = 74880
Step 193: 74880 + 390 = 75270
Step 194: 75270 + 390 = 75660
Step 195: 75660 + 390 = 76050
Step 196: 76050 + 390 = 76440
Step 197: 76440 + 390 = 76830
Step 198: 76830 + 390 = 77220
Step 199: 77220 + 390 = 77610
Step 200: 77610 + 390 = 78000
Step 201: 78000 + 390 = 78390
Step 202: 78390 + 390 = 78780
Step 203: 78780 + 390 = 79170
Step 204: 79170 + 390 = 79560
Step 205: 79560 + 390 = 79950

So, 390*205 = 79950